Cam and like grinding machine



Jan. 17, 1933. MAW-ER 1,894,382

CAM AND LIKE GRINDING MACHINE Filed April 30. 1930 N VfN 70K Patented Jan. 17, 1933' UNET STATES PATENT OFFICE LI! WELYN MAWER, OF IBISHOPSTON, BRISTOL, ENGLAND, ASSIGNOR F ONE-HALF" TO THE CHURCHILL MACHINE TOOL COMPANY LIMITED, 015 MANCHESTER, ENGLAND,

A BRITISH COMPANY CAM AND LIKE GRINDING MACHINE Application filed April so, 1930, Serial No. 448,732, and in Great BritainNovember is, 1929.

This invention relates to machines for the grinding or milling of cams (such as are used carrying the cam or like workpiece during the grinding or milling operation, the drive to the workpiece shallrotate' the same with a uniform angular velocity. A further ob ect of the invention is to provide means for ensuring that the reaction of the braking device usually associated with the drive to the work I piece for ensuring a steady drive shall not affect the said swinging movements of the work carrying head.

My invention comprises the comb nation with the spindle about the axis of whlch the workpiece is rotated, and which is capable of movement away from and towards the grinding wheel or milling cutter, of driving means for the workpiece also adaptedto turn about said axis, and means constitutlng a parallel linkage system for regulating the movement of the driving means relatively to the splndle during the swinging movements of the latter. I

My invention further comprlses the arrangement wherein the brake applied to the drive of the spindle by which the workpiece is rotated, has its reaction borne by the machine through the frame of the spindle drlving means and the linkage system.

Referring to the accompanylng sheet of explanatory drawings Figure 1 is an elevation with the work spindle driving gear in section showing the swinging head of a grinding machine arranged in accordance with my invention.

Figure 2 is an end view of the swinging head upon the machine bed.

Figure 3 is a sectional end view on the line A A of Figure 1.

Figure 4 is a plan view of the parts.

Figure 5 is a diagram illustrating the action of the parallel linkage system when the swinging head is displaced.

The same reference letters in the different views indicate the same parts.

The swinging head a is carried by its trunnions b in the bed 0-...of themachine in the known manner. The work spindle d is mounted in bearings in brackets. upon. the head a and carries thereon a master cam e and a work driving plate f. The workpiece is mounted between the centres g and h or may be mounted in a chuck upon the end of the spindle (Z. The swinging head a has a weighto(not shown) acting thereon to hold the master cam e in contact with a roller 2' in a bracket upon the bed'c of the machine, so that as the spindle d is rotated, a swinging movement is imparted to the head a.

Upon the spindle cZ iskeyed a spur wheel a j whichhas extended bosses to carry the frame is through the medium of the ball bearings m. The Wheel 9' is rotated by the pinion n on the shaft 0 with the pulley p thereon. The

frame is has a lug g towhich one end of a link i r is pivotally attached, the other end of the gnr being pivotally attached to the machine The wheel j has a projecting ring 8 thereon upon which a brake band 25 can be contracted. by the bolt u' and knurled nut 22, see Figure 3. The bolt passes through the frame /a as shown, and the reaction ofthe brake is transmitted to the frame by the nut o.

The distance between the centres of the piv-- ots at the ends of the link 1 is the same as the distance between the axis of the spindle d and the axis of the trunnions I) Also when the axis of d is vertically above the axis of b the link 7 is Vertical. The arrangement there-- fore constitutes a parallel linkage system as ing wheel w is shown acting upon the nose of a cam 3 The swinging movement of the head a does not therefore affect the drive within the frame 70 so that the angular rate of rotation of the workpiece does not vary during such movement.

As the reaction of the brake t is borne through the frame 1c and the linkage system by the bed of the machine, the brake does not exert any restraint uponthe free swinging movements of the head a.

What I claim is 1. In cam and like grinding and milling machines, the combination of a grinding Wheel, a Work spindle, a machine bed, a swinging head 'mounted on said bed, trunnions for said swinging head, a gear driving and rotating upon the same axis as said work spindle, a ,frame mounted on said swinging head and housing said gear, a lug on said frame, a pinion carried by said frame and driving said driving gear, a link one end of which is'pivotally connected tosaid lug and the other end to said machine bed, the distance between the pivots of said link being equal to the distance between the axis of said trunnions and the axis of said driving gear and constituting a parallel linkage system which together with the fact that said pinion is mounted in the same frame as said driving gear, ensures that said work spindle is rotated with uniform angular velocity.

2. In cam and like grinding and milling machines as claimed in claim 1, the combination with the driving gear of a brake ring and a brake acting upon said ring and having its reaction transmitted to the machine" bed through the frame carrying the Work spindle drivinggear and linkage system.

In testimony'whereofI have signed my 3g name to this specification.

'LLYWELYN MAWER. 

